The effects of morphine upon several neuroendocrine functions of the brain will be studied in this proposal. Five neuropeptide systems have been chosen; these are (1) the beta-endorphin (POMC) neurons (crucial to the central effects of morphine), (2) the alpha MSH-specific system, (3) vasopressin (AVP, (4) corticotropin releasing factor (CRF), and (5) thyrotropin releasing factor (TRF). A newly developed isolation technique will be used to prepare cultures of pure populations of POMC, AVP, and CRF neurons from the hypothalami of normal and morphine-treated animals. Beta-endorphin (POMC) neurons will be studied in detail with respect to: (1) early post-translational processing, and upon acetylation of POMC peptides, particularly beta-endorphin and alpha-MSH, (2) interactions with TRF which may be an endogenous antagonist, (3) gastric, which may coexist in the POMC neuron, and (4) their (opiate) pre- and postsynaptic receptors.